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Abstract:

The present invention relates to an auxiliary composition, for use in the
laundering or treatment of fabrics, comprising an admix of (i) clay and
(ii) a silicone in an emulsified form.

Claims:

1. A process for preparing an auxiliary composition comprising the steps
of:i) contacting a silicone comprising polydimethylsiloxane with water,
and optionally an emulsifier, to form a silicone in an emulsified
form;ii) contacting the silicone in an emulsified form with a clay to
form an admix of clay and a silicone in an emulsified form; andiii)
agglomerating said admix of clay and silicone in an emulsified form.

2. The process of claim 1, wherein said silicone in an emulsified form
comprising a oil-in-water emulsion.

3. The process of claim 1, wherein said silicone further comprises a
second silicone.

4. The process of claim 1, wherein the second silicone is an
amino-silicone.

5. The process of claim 1, comprising an emulsifier comprising a detersive
surfactant and the weight ratio of silicone to emulsifier is from 3:1 to
20:1.

6. The process of claim 1, wherein the silicone comprises a silicone
mixture of two or more different types of silicone.

7. The process of claim 6, wherein the silicone mixtures comprises: a
high-viscosity silicone and a low viscosity silicone; a functionalised
silicone and a non-functionalised silicone; or a non-charged silicone
polymer and a cationic silicone polymer.

[0002]The present invention relates to a composition for use in the
laundering or treatment of fabrics. More specifically, the present
invention relates to a laundry detergent composition capable of both
cleaning and softening fabric during a laundering process. The present
invention also relates to a process for making the above composition.

BACKGROUND

[0003]Laundry detergent compositions that both clean and soften fabric
during a laundering process are known and have been developed and sold by
laundry detergent manufacturers for many years. Typically, these laundry
detergent compositions comprise components that are capable of providing
a fabric-softening benefit to the laundered fabric; such fabric-softening
components include clays and silicones.

[0004]The incorporation of clay into laundry detergent compositions to
impart a fabric-softening benefit to the laundered fabric is described in
the following references. A granular, built laundry detergent composition
comprising a smectite clay that is capable of both cleaning and softening
a fabric during a laundering process is described in U.S. Pat. No.
4,062,647 (Storm, T. D., and Nirschl, J. P.; The Procter & Gamble
Company). A heavy duty fabric-softening detergent comprising bentonite
clay agglomerates is described in GB 2 138 037 (Allen, E., Coutureau, M.,
and Dillarstone, A.; Colgate-Palmolive Company). Laundry detergents
compositions containing fabric-softening clays of between 150 and 2,000
microns in size are described in U.S. Pat. No. 4,885,101 (Tai, H. T.;
Lever Brothers Company). The fabric-softening performance of
clay-containing laundry detergent compositions is improved by the
incorporation of a flocculating aid to the clay-containing laundry
detergent composition. For example, a detergent composition comprising a
smectite type clay and a polymeric clay-flocculating agent is described
in EP 0 299 575 (Raemdonck, H., and Busch, A.; The Procter & Gamble
Company).

[0005]The use of silicones to provide a fabric-softening benefit to
laundered fabric during a laundering process is also known. U.S. Pat. No.
4,585,563 (Busch, A., and Kosmas, S.; The Procter & Gamble Company)
describes that specific organo-functional polydialkylsiloxanes can
advantageously be incorporated in granular detergents to provide
remarkable benefits inclusive of through-the-wash softening and further
textile handling improvements. U.S. Pat. No. 5,277,968 (Canivenc, E.;
Rhone-Poulenc Chemie) describes a process for the conditioning of textile
substrates to allegedly impart a pleasant feel and good hydrophobicity
thereto, comprising treating such textile substances with an effective
conditioning amount of a specific polydiorganosiloxane.

[0006]Detergent Manufacturers have attempted to incorporate both clay and
silicone in the same laundry detergent composition. For example,
siliconates were incorporated in clay-containing compositions to
allegedly improve their dispensing performance. U.S. Pat. No. 4,419,250
(Allen, E., Dillarstone, R., and Reul, J. A.; Colgate-Palmolive Company)
describes agglomerated bentonite particles that comprise a salt of a
lower alkyl siliconic acid and/or a polymerization product(s) thereof.
U.S. Pat. No. 4,421,657 (Allen, E., Dillarstone, R., and Reul, J. A.;
Colgate-Palmolive Company) describes a particulate heavy-duty laundering
and textile-softening composition comprising bentonite clay and a
siliconate. U.S. Pat. No. 4,482,477 (Allen, E., Dillarstone, R., and
Reul, J. A.; Colgate-Palmolive Company) describes a particulate built
synthetic organic detergent composition which includes a dispensing
assisting proportion of a siliconate and preferably bentonite as a
fabric-softening agent. In another example, EP 0 163 352 (York, D. W.;
The Procter & Gamble Company) describes the incorporation of silicone
into a clay-containing laundry detergent composition in an attempt to
control the excessive suds that are generated by the clay-containing
laundry detergent composition during the laundering process. EP 0 381 487
(Biggin, I. S., and Cartwright, P. S.; BP Chemicals Limited) describes an
aqueous based liquid detergent formulation comprising clay that is
pretreated with a barrier material such as a polysiloxane.

[0007]Detergent manufacturers have also attempted to incorporate a
silicone, clay and a flocculant in a laundry detergent composition. For
example, a fabric treatment composition comprising substituted
polysiloxanes, softening clay and a clay flocculant is described in
WO92/07927 (Marteleur, C. A. A. V. J., and Convents, A. C.; The Procter &
Gamble Company).

[0008]More recently, fabric care compositions comprising an organophilic
clay and functionalised oil are described in U.S. Pat. No. 6,656,901 B2
(Moorfield, D., and Whilton, N.; Unilever Home & Personal Care USA
division of Conopco, Inc.). WO02/092748 (Instone, T. et al; Unilever PLC)
describes a granular composition comprising an intimate blend of a
non-ionic surfactant and a water-insoluble liquid, which may a silicone,
and a granular carrier material, which may be a clay. WO03/055966
(Cocardo, D. M., et al; Hindustain Lever Limited) describes a fabric care
composition comprising a solid carrier, which may be a clay, and an
anti-wrinkle agent, which may be a silicone.

[0009]However, despite all of the above attempts, whatever improved
fabric-softening performance benefit detergent manufacturers have been
able to achieve for a laundry detergent has come at the expense of its
fabric-cleaning performance and also its processability. Therefore, there
is still a need to improve the fabric-softening performance of a laundry
detergent composition without unduly negatively affecting its
fabric-cleaning performance and processability.

SUMMARY

[0010]The present invention overcomes the above mentioned problem by
providing an auxiliary composition, for use in the laundering or
treatment of fabrics, comprising an admix of (i) clay and (ii) silicone
in an emulsified form.

DESCRIPTION

Clay

[0011]Typically, the clay is a fabric-softening clay such as a smectite
clay. Preferred smectite clays are beidellite clays, hectorite clays,
laponite clays, montmorillonite clays, nontonite clays, saponite clays
and mixtures thereof. Preferably, the smectite clay is a dioctahedral
smectite clay, more preferably a montmorillonite clay. Dioctrahedral
smectite clays typically have one of the following two general formulae:

NaxAl2-xMgxSi4O10(OH)2 Formula (I)

or

CaxAl2-xMgxSi4O10(OH)2 Formula (II)

[0012]wherein x is a number from 0.1 to 0.5, preferably from 0.2 to 0.4.

[0013]Preferred clays are low charge montmorillonite clays (also known as
a sodium montmorillonite clay or Wyoming type montmorillonite clay) which
have a general formula corresponding to formula (I) above. Preferred
clays are also high charge montmorillonite clays (also known as a calcium
montmorillonite clay or Cheto type montmorillonite clay) which have a
general formula corresponding to formula (II) above. Preferred clays are
supplied under the tradenames: Fulasoft 1 by Arcillas Activadas Andinas;
White Bentonite STP by Fordamin; and Detercal P7 by Laviosa Chemica
Mineraria SPA.

[0014]The clay may be a hectorite clay. Typical hectorite clay has the
general formula:

[0015]wherein y=0 to 0.4, if y=>0 then MeIII is Al, Fe or B,
preferably y=0; Mn+ is a monovalent (n=1) or a divalent (n=2) metal
ion, preferably selected from Na, K, Mg, Ca and Sr. x is a number from
0.1 to 0.5, preferably from 0.2 to 0.4, more preferably from 0.25 to
0.35. z is a number from 0 to 2. The value of (x+y) is the layer charge
of the clay, preferably the value of (x+y) is in the range of from 0.1 to
0.5, preferably from 0.2 to 0.4, more preferably from 0.25 to 0.35. A
preferred hectorite clay is that supplied by Rheox under the tradename
Bentone HC. Other preferred hectorite clays for use herein are those
hectorite clays supplied by CSM Materials under the tradename Hectorite U
and Hectorite R, respectively.

[0017]The clay may also be a light coloured crystalline clay mineral,
preferably having a reflectance of at least 60, more preferably at least
70, or at least 80 at a wavelength of 460 nm. Preferred light coloured
crystalline clay minerals are china clays, halloysite clays, dioctahedral
clays such as kaolinite, trioctahedral clays such as antigorite and
amesite, smectite and hormite clays such as bentonite (montmorillonite),
beidilite, nontronite, hectorite, attapulgite, pimelite, mica, muscovite
and vermiculite clays, as well as pyrophyllite/talc, willemseite and
minnesotaite clays. Preferred light coloured crystalline clay minerals
are described in GB2357523A and WO01/44425.

[0018]Preferred clays have a cationic exchange capacity of at least 70
meq/100 g. The cationic exchange capacity of clays can be measured using
the method described in Grimshaw, The Chemistry and Physics of Clays,
Interscience Publishers, Inc., pp. 264-265 (1971).

[0019]Preferably, the clay has a weight average primary particle size,
typically of greater than 20 micrometers, preferably more than 23
micrometers, preferably more than 25 micrometers, or preferably from 21
micrometers to 60 micrometers, more preferably from 22 micrometers to 50
micrometers, more preferably from 23 micrometers to 40 micrometers, more
preferably from 24 micrometers to 30 micrometers, more preferably from 25
micrometers to 28 micrometers. Clays having these preferred weight
average primary particle sizes provide a further improved
fabric-softening benefit. The method for determining the weight average
particle size of the clay is described in more detail hereinafter.

Method for Determining the Weight Average Primary Particle Size of the
Clay:

[0020]The weight average primary particle size of the clay is typically
determined using the following method: 12 g clay is placed in a glass
beaker containing 250 ml distilled water and vigorously stirred for 5
minutes to form a clay solution. The clay is not sonicated, or
microfluidised in a high pressure microfluidizer processor, but is added
to said beaker of water in an unprocessed form (i.e. in its raw form). 1
ml clay solution is added to the reservoir volume of an Accusizer 780
single-particle optical sizer (SPOS) using a micropipette. The clay
solution that is added to the reservoir volume of said Accusizer 780 SPOS
is diluted in more distilled water to form a diluted clay solution; this
dilution occurs in the reservoir volume of said Accusizer 780 SPOS and is
an automated process that is controlled by said Accusizer 780 SPOS, which
determines the optimum concentration of said diluted clay solution for
determining the weight average particle size of the clay particles in the
diluted clay solution. The diluted clay solution is left in the reservoir
volume of said Accusizer 780 SPOS for 3 minutes. The clay solution is
vigorously stirred for the whole period of time that it is in the
reservoir volume of said Accusizer 780 SPOS. The diluted clay solution is
then sucked through the sensors of said Accusizer 780 SPOS; this is an
automated process that is controlled by said Accusizer 780 SPOS, which
determines the optimum flow rate of the diluted clay solution through the
sensors for determining the weight average particle size of the clay
particles in the diluted clay solution. All of the steps of this method
are carried out at a temperature of 20° C. This method is carried
out in triplicate and the mean of these results determined.

Silicone

[0021]The silicone is preferably a fabric-softening silicone. The silicone
typically has the general formula:

##STR00001##

[0022]wherein, each R1 and R2 in each repeating unit,
--(Si(R1)(R2)O)--, are independently selected from branched or
unbranched, substituted or unsubstituted C1-C10 alkyl or
alkenyl, substituted or unsubstituted phenyl, or units of
-[--R1R2Si--O--]-; x is a number from 50 to 300,000, preferably
from 100 to 100,000, more preferably from 200 to 50,000; wherein, the
substituted alkyl, alkenyl or phenyl are typically substituted with
halogen, amino, hydroxyl groups, quaternary ammonium groups, polyalkoxy
groups, carboxyl groups, or nitro groups; and wherein the polymer is
terminated by a hydroxyl group, hydrogen or --SiR3, wherein, R3
is hydroxyl, hydrogen, methyl or a functional group.

[0023]Suitable silicones include: amino-silicones, such as those described
in EP150872, WO92/01773 and U.S. Pat. No. 4,800,026;
quaternary-silicones, such as those described in U.S. Pat. No. 4,448,810
and EP459821; high-viscosity silicones, such as those described in
WO00/71806 and WO00/71807; modified polydimethylsiloxane; functionalized
polydimethyl siloxane such as those described in U.S. Pat. No. 5,668,102.
Preferably, the silicone is a polydimethylsiloxane.

[0024]The silicone may preferably be a silicone mixture of two or more
different types of silicone. Preferred silicone mixtures are those
comprising: a high-viscosity silicone and a low viscosity silicone; a
functionalised silicone and a non-functionalised silicone; or a
non-charged silicone polymer and a cationic silicone polymer.

[0025]The silicone typically has a viscosity, of from 5,000 cp to
5,000,000 cp, or from greater than 10,000 cp to 1,000,000 cp, or from
10,000 cp to 600,000 cp, more preferably from 50,000 cp to 400,000 cp,
and more preferably from 80,000 cp to 200,000 cp when measured at a shear
rate of 20 s-1 and at ambient conditions (20° C. and 1
atmosphere). The silicone is typically in a liquid or liquefiable form,
especially when admixed with the clay. Typically, the silicone is a
polymeric silicone comprising more than 3, preferably more than 5 or even
more than 10 siloxane monomer units.

[0026]The silicone is in the form of an emulsion, especially when admixed
with the clay. The emulsion can be a water-in oil emulsion or an oil-in
water emulsion. The emulsion is preferably in the form of a water-in-oil
emulsion with the silicone forming at least part, and preferably all, of
the continuous phase, and the water forming at least part, and preferably
all, of the discontinuous phase. The emulsion typically has a volume
average primary droplet size of from 0.1 micrometers to 5,000
micrometers, preferably from 0.1 micrometers to 50 micrometers, and most
preferably from 0.1 micrometers to 5 micrometers. The volume average
primary particle size is typically measured using a Coulter
Multisizer® or by the method described in more detail below.

[0027]The silicone in emulsified form typically has a viscosity of from
500 cp to 70,000 cp, or from 3,000 cp to 20,000 cp.

[0028]Commercially available silicone oils that are suitable for use are
DC200® (12,500 cp to 600,000 cp), supplied by Dow Corning, or
silicones of the Baysilone Fluid M series supplied by GE Silicone.
Alternatively, preformed silicone emulsions are also suitable for use.
These emulsions may comprise water and/or other solvents in an effective
amount to aid the emulsification of the silicone.

Method for Determining the Volume Average Proplet Size of the Silicone:

[0029]The volume average droplet size of the emulsion is typically
determined by the following method: An emulsion is applied to a
microscope slide with the cover slip being gently applied. The emulsion
is observed at 400× and 1,000× magnification under the
microscope and the average droplet size of the emulsion is calculated by
comparison with a standard stage micrometer.

[0032]The charged polymeric fabric-softening boosting component may be a
cationic polymer that comprises (i) acrylamide monomer units, (ii) other
cationic monomer units and (iii) optionally, other monomer units. The
charged polymeric fabric-softening boosting component may be a
cationically-modified polyacrylamide or co-polymer thereof; any cationic
modification can be used for these polyacrylamides. Highly preferred
charged polymeric fabric-softening boosting components are co-polymers of
acrylamide and a methyl chloride quaternary salt of dimethylaminoethyl
acrylate (DMA3-MeCl), for example such as those supplied by BASF,
Ludwigshafen, Germany, under the tradename Sedipur CL343.

[0033]The general structure for DMA3MeCl is:

##STR00002##

[0034]The general structure of acrylamide is:

##STR00003##

[0035]Preferred cationic polymers have the following general structure:

##STR00004##

[0036]wherein n and m independently are numbers in the range of from 100
to 100,000, preferably from 800 to 3400. The molar ratio of n:m is
preferably in the range of from 4:1 to 3:7, preferably from 3:2 to 2:3.

[0037]Suitable charged polymeric fabric-softening boosting components are
described in more detail in, and can be synthesized according to the
methods described in, DE10027634, DE10027636, DE10027638, U.S. Pat. No.
6,111,056, U.S. Pat. No. 6,147,183, WO98/17762, WO98/21301, WO01/05872
and, WO01/05874.

[0038]The charged polymeric fabric-softening boosting component preferably
has an average degree of cationic substitution of from 1% to 70%,
preferably from above 10% to 70%, more preferably from 10% to 60%. If the
charged polymeric fabric-softening boosting component is a cationic guar
gum, then preferably its degree of cationic substitution is from 10% to
15%. However, if the charged polymeric fabric-softening boosting
component is a polymer having a general structure according to formula
VII above, then preferably its degree of cationic substitution is from
40% to 60%. The average degree of cationic substitution typically means
the molar percentage of monomers in the cationic polymer that are
cationically substituted. The average degree of cationic substitution can
be determined by any known methods, such as colloid titration. One such
colloid titration method is described in more detail by Horn, D., in
Prog. Colloid &Polymer Sci., 1978, 8, p 243-265.

[0039]The charged polymeric fabric-softening boosting component preferably
has a charge density of from 0.2 meq/g to 1.5 meq/g. The charge density
is typically defined in terms of the number of charges carried by the
polymer, expressed in milliequivalents/gram. One equivalent is the weight
of the material required to give one mole of charge; one milliequivalent
is a thousandth of this.

Method for Determining the Weight Average Molecular Weight of the Charged
Polymeric Fabric-Softening Boosting Component:

[0041]1. Dissolve 1.5 g of polymer in 1 litre of deionised water.
[0042]2. Filter the mixture obtained in step 1, using a Sartorius
Minisart RC25 filter. [0043]3. According the manufacturer's instructions,
inject 100 litres of the mixture obtained in step 2, on a GPC machine
that is fitted with a Suprema MAX (8 mm by 30 cm) column operating at
35° C. and a ERC7510 detector, with 0.2M aqueous solution of
acetic acid and potassium chloride solution being used as an elution
solvent at a flux of 0.8 ml/min. [0044]4. The weight average molecular
weight is obtained by analysing the data from the GPC according to the
manufacturer's instructions.

Flocculating Aid

[0045]The flocculating aid is capable of flocculating clay. Typically, the
flocculating aid is polymeric. Preferably the flocculating aid is a
polymer comprising monomer units selected from the group consisting of
ethylene oxide, acrylamide, acrylic acid and mixtures thereof. Preferably
the flocculating aid is a polyethyleneoxide. Typically the flocculating
aid has a molecular weight of at least 100,000 Da, preferably from
150,000 Da to 5,000,000 Da and most preferably from 200,000 Da to 700,000
Da.

[0047]The auxiliary composition is for use in the laundering or treatment
of fabrics and typically either forms part of a fully formulated laundry
detergent composition or is an additive composition, suitable for
addition to a fully formulated laundry detergent composition. Preferably,
the auxiliary composition forms part of a fully formulated laundry
detergent composition.

[0048]The auxiliary composition comprises an admix of clay and a silicone
in an emulsified form. Typically, the auxiliary composition additionally
comprises a charged polymeric fabric-softening boosting component and
optionally one or more adjunct components. Preferably, the charged
polymeric fabric-softening boosting component is present in the auxiliary
composition in the form of an admix with the clay and the silicone; this
means that typically, the charged polymeric fabric-softening boosting
component is present in the same particle as the clay and silicone.

[0049]Preferably, the weight ratio of the silicone to emulsifier, if
present, in the auxiliary composition is from 3:1 to 20:1. Preferably,
the weight ratio of silicone to clay is from 0.05 to 0.3.

Laundry Detergent Composition

[0050]The laundry detergent composition comprises the auxiliary
composition, a detersive surfactant, optionally a flocculating aid,
optionally a builder and optionally a bleach. The laundry detergent
composition optionally comprises one or more other adjunct components.

[0051]The laundry detergent composition is preferably in particulate form,
preferably in free-flowing particulate form, although the composition may
be in any liquid or solid form. The composition in solid form can be in
the form of an agglomerate, granule, flake, extrudate, bar, tablet or any
combination thereof. The solid composition can be made by methods such as
dry-mixing, agglomerating, compaction, spray drying, pan-granulation,
spheronization or any combination thereof. The solid composition
preferably has a bulk density of from 300 g/l to 1,500 g/l, preferably
from 500 g/l to 1,000 g/l.

[0052]The composition may also be in the form of a liquid, gel, paste,
dispersion, preferably a colloidal dispersion or any combination thereof.
Liquid compositions typically have a viscosity of from 500 cps to 3,000
cps, when measured at a shear rate of 20 s-1 at ambient conditions
(20° C. and 1 atmosphere), and typically have a density of from
800 g/l to 1300 g/l. If the composition is in the form of a dispersion,
then it will typically have a volume average particle size of from 1
micrometer to 5,000 micrometers, preferably from 1 micrometer to 50
micrometers. The particles that form the dispersion are usually the clay
and, if present, the silicone. Typically, a Coulter Multisizer is used to
measure the volume average particle size of a dispersion.

[0053]The composition may in unit dose form, including not only tablets,
but also unit dose pouches wherein the composition is at least partially
enclosed, preferably completely enclosed, by a film such as a polyvinyl
alcohol film.

[0054]The composition is capable of both cleaning and softening fabric
during a laundering process. Typically, the composition is formulated for
use in an automatic washing machine, although it can also be formulated
for hand-washing use.

[0055]The following adjunct components and levels thereof, when
incorporated into a laundry detergent composition of the present
invention, further improve the fabric-softening performance and
fabric-cleaning performance of the laundry detergent composition: at
least 10% by weight of the composition of alkyl benzene sulphonate
detersive surfactant; at least 0.5%, or at least 1%, or even at least 2%
by weight of the composition of cationic quaternary ammonium detersive
surfactant; at least 1% by weight of the composition alkoxylated alkyl
sulphate detersive surfactant, preferably ethoxylated alkyl sulphate
detersive surfactant; less than 12% or even less than 6%, or even 0%, by
weight of the composition zeolite builder; and any combination thereof.
Preferably the laundry detergent composition comprises at least 6%, or
even at least 8%, or even at least 12%, or even at least 18%, by weight
of the laundry detergent composition of the auxiliary composition.
Preferably the composition comprises at least 0.3% by weight of the
composition of a flocculating aid. The weight ratio of clay to
flocculating aid in the laundry detergent composition is preferably in
the range of from 10:1 to 200:1, preferably from 14:1 to 160:1 more
preferably from 20:1 to 100:1 and more preferably from 50:1 to 80:1.

Process

[0056]The process for making the auxiliary composition comprises the steps
of (i) contacting a silicone with water, and optionally an emulsifier, to
form a silicone in an emulsified form; and (ii) thereafter contacting the
silicone in an emulsified form with clay to form an admix of clay and a
silicone.

[0057]Preferably the silicone is in a liquid or liquefiable form when it
is contacted to the clay in step (ii). Preferably the emulsion formed in
step (i) is a water-in-oil emulsion with the silicone forming at least
part of, and preferably all of, the continuous phase of the emulsion, and
the water forms at least part of, and preferably all of, the discontinous
phase of the emulsion.

[0058]Preferably, a charged polymeric fabric-softening boosting component
is contacted to the clay and silicone in step (ii). The intimate mixing
of the charged polymeric fabric-softening boosting component with the
clay and silicone further improves the fabric-softening performance of
the resultant auxiliary composition.

[0059]Step (i) may be carried out at ambient temperature (e.g. 20°
C.), but it may be preferred that step (i) is carried out at elevated
temperature such as a temperature in the range of from 30° C. to
60° C. If an emulsifier is used in the process, then preferably
the emulsifier is contacted to water to form an emulsifier-water mixture,
thereafter the emulsifier-water mixture is contacted to the silicone. For
continuous processes, step (i) is typically carried out in an in-line
static mixer or an in-line dynamic (shear) mixer. For non-continuous
processes, step (i) is typically carried out in a batch mixer such as a
Z-blade mixer, anchor mixer or a paddle mixer.

[0060]The admix of clay and silicone is preferably subsequently
agglomerated in a high-sheer mixer. Suitable high-sheer mixers include CB
Loedige mixers, Schugi mixers, Littleford mixers, Drais mixers and lab
scale mixers such as Braun mixers. Preferably the high-sheer mixer is a
pin mixer such as a CB Loedige mixer or Littleford mixer or Drais mixer.
The high-sheer mixers are typically operated at high speed, preferably
having a tip speed of from 30 ms-1 to 35 ms-1. Preferably water
is added to the high-sheer mixer.

[0061]The admix of clay and silicone are typically subsequently subjected
to a conditioning step in a low-shear mixer. Suitable low-shear mixers
include Ploughshear mixers such as a Loedige KM. Preferably the low-shear
mixer has a tip speed of from 5 ms-1 to 10 ms-1. Optionally,
fine particles such as zeolite and/or clay particles, typically having an
average particle size of from 1 micrometer to 40 micrometers or even from
1 micrometer to 10 micrometers are introduced into the low-shear mixer.
This dusting step improves the flowability of the resultant particles by
reducing their stickiness and controlling their growth.

[0062]The admix of clay and silicone is typically subjected to a sizing
step, wherein particles having a particle size of greater than 500 mm are
removed from the admix. Typically, these large particles are removed from
the admix by sieving.

[0063]The admix of clay and silicone is preferably subjected to hot air
having a temperature of greater than 50° C. or even greater than
100° C. Typically, the admix of clay and silicone is dried at an
elevated temperature (e.g. a temperature of greater than 50° C. or
even greater than 100° C.); preferably, the admix is dried in a
low-shear apparatus such as fluid bed drier. Following this preferred
drying step, the admix of clay and silicone is preferably thereafter
subjected to cold air having a temperature of less than 15° C.,
preferably from 1° C. to 10° C. This cooling step is
preferably carried out in a fluid bed cooler.

[0064]The admix of clay and silicone is preferably subjected to a second
sizing step, wherein particles having a particle size of less than 250
micrometers are removed from the admix. These small particles are removed
from the admix by sieving and/or elutriation. If elutriation is used,
then preferably the second sizing step is carried out in a fluid bed such
as the fluid bed dryer and/or cooler, if used in the process.

[0065]The admix of clay and silicone is preferably subjected to a third
sizing step, wherein particles having a particle size of greater than
1,400 micrometers are removed from the admix. These large particles are
removed from the admix by sieving.

[0066]The large particles that are optionally removed from the admix
during the first and/or third sizing steps are typically recycled back to
the high sheer mixer and/or to the fluid bed dryer or cooler, if used in
the process. Optionally, these large particles are subjected to a
grinding step prior to their introduction to the high sheer mixer and/or
fluid bed dryer or cooler. The small particles that are optionally
removed from the admix during the second sizing step are typically
recycled back to the high sheer mixer and/or low shear mixer, if used in
the process.

EXAMPLES

Example 1

A Process for Preparing a Silicone Emulsion

[0067]81.9 g of silicone (polydimethylsiloxane) having a viscosity of
100,000 cp is added to a beaker. 8.2 g of 30 w/w % aqueous
C11-C13 alkyl benzenesulphonate (LAS) solution is then added
the beaker and the silicone, LAS and water are mixed thoroughly by hand
using a flat knife for 2 minutes to form an emulsion.

Example 2

A Process for Making a Clay/Silicone Agglomerate

[0068]601.2 g of bentonite clay and 7.7 g of cationic guar gum are added
to a Braun mixer. 90.1 g of the emulsion of example 1 is added to the
Braun mixer, and all of the ingredients in the mixer are mixed for 10
seconds at 1,100 rpm (speed setting 8). The speed of the Braun mixer is
then increased to 2,000 rpm (speed setting 14) and 50 g water is added
slowly to the Braun mixer. The mixer is kept at 2,000 rpm for 30 seconds
so that wet agglomerates are formed. The wet agglomerates are transferred
to a fluid bed dried and dried for 4 minutes at 137° C. to form
dry agglomerates. The dry agglomerates are sieved to removed agglomerates
having a particle size greater than 1,400 micrometers and agglomerates
having a particle size of less than 250 micrometers.